java - Obfuscating source code using proguard -

i want obfuscate source code using java obfuscators. used proguard suggested one. configured build.xml follow

<target name="-post-jar">     <property name="proguard.jar.path" value="d:/pro/proguard.jar" />     <taskdef resource="proguard/ant/task.properties"              classpath="${proguard.jar.path}" />     <echo message="obfuscating ${dist.jar}..."/>     <mkdir dir="${build.dir}/obfuscated"/>     <proguard printmapping="${build.dir}/obfuscated/${application.title}.map"               renamesourcefileattribute="sourcefile" ignorewarnings="true">          <injar  file="${dist.jar}" />         <outjar file="${build.dir}/obfuscated/${application.title}.jar" />          <libraryjar path="${javac.classpath}" />                   <libraryjar file="${java.home}/lib/rt.jar" />         <libraryjar file="${java.home}/lib/jce.jar" />          <keepattribute name="innerclasses" />         <keepattribute name="sourcefile" />         <keepattribute name="linenumbertable" />         <keepattribute name="deprecated" />         <keepattribute name="*annotation*" />         <keepattribute name="signature" />         <keepattribute name="exceptions" />          <keep access="public">             <field  access="public protected" />             <method access="public protected" />         </keep>          <keepclassmembernames access="public">             <method type      ="java.lang.class"                     name      ="class$"                     parameters="java.lang.string" />             <method type      ="java.lang.class"                     name      ="class$"                     parameters="java.lang.string,boolean" />         </keepclassmembernames>          <keepclasseswithmembernames>             <method access="native" />         </keepclasseswithmembernames>          <keepclassmembers extends="java.lang.enum">             <method access="public static"                     type="**[]"                     name="values"                     parameters="" />             <method access="public static"                     type="**"                     name="valueof"                     parameters="java.lang.string" />         </keepclassmembers>          <keepnames implements="java.io.serializable"/>         <keepclassmembers implements="java.io.serializable">             <field  access    ="final"                     type      ="long"                     name      ="serialversionuid" />             <field  access    ="!static !transient"                     name      ="**"/>             <field  access    ="!private"                     name      ="**"/>             <method access    ="!private"                     name      ="**"/>             <method access    ="private"                     type      ="void"                     name      ="writeobject"                     parameters="java.io.objectoutputstream" />             <method access    ="private"                     type      ="void"                     name      ="readobject"                     parameters="java.io.objectoutputstream" />             <method type      ="java.lang.object"                     name      ="writereplace"                     parameters="" />             <method type      ="java.lang.object"                     name      ="readresolve"                     parameters="" />         </keepclassmembers>      </proguard>     <copy file="${build.dir}/obfuscated/${application.title}.jar" tofile="${dist.jar}" overwrite="true"/>     <delete dir="${build.dir}/obfuscated"/> </target>    

but results in following error :

java.lang.unsupportedoperationexception: method must overridden in [proguard.optimize.peephole.classmerger] if ever called     @ proguard.classfile.util.simplifiedvisitor.visitanyclass(simplifiedvisitor.java:47)     @ proguard.classfile.util.simplifiedvisitor.visitlibraryclass(simplifiedvisitor.java:59)     @ proguard.classfile.libraryclass.accept(libraryclass.java:301)     @ proguard.classfile.programclass.subclassesaccept(programclass.java:433)     @ proguard.optimize.peephole.verticalclassmerger.visitprogramclass(verticalclassmerger.java:83)     @ proguard.classfile.programclass.accept(programclass.java:346)     @ proguard.classfile.classpool.classesaccept(classpool.java:125)     @ proguard.optimize.optimizer.execute(optimizer.java:565)     @ proguard.proguard.optimize(proguard.java:307)     @ proguard.proguard.execute(proguard.java:116)     @ proguard.ant.proguardtask.execute(proguardtask.java:316)     @ org.apache.tools.ant.unknownelement.execute(unknownelement.java:291)     @ sun.reflect.generatedmethodaccessor137.invoke(unknown source)     @ sun.reflect.delegatingmethodaccessorimpl.invoke(delegatingmethodaccessorimpl.java:25)     @ java.lang.reflect.method.invoke(method.java:597)     @ org.apache.tools.ant.dispatch.dispatchutils.execute(dispatchutils.java:106)     @ org.apache.tools.ant.task.perform(task.java:348)     @ org.apache.tools.ant.target.execute(target.java:392)     @ org.apache.tools.ant.target.performtasks(target.java:413)     @ org.apache.tools.ant.project.executesortedtargets(project.java:1399)     @ org.apache.tools.ant.project.executetarget(project.java:1368)     @ org.apache.tools.ant.helper.defaultexecutor.executetargets(defaultexecutor.java:41)     @ org.apache.tools.ant.project.executetargets(project.java:1251)     @ org.apache.tools.ant.module.bridge.impl.bridgeimpl.run(bridgeimpl.java:285)     @ org.apache.tools.ant.module.run.targetexecutor.run(targetexecutor.java:539)     @ org.netbeans.core.execution.runclassthread.run(runclassthread.java:153) 

instead of using option -ignorewarnings, should try solving warnings get. don't mention warnings in question, chances have specified library classes (with -libraryjars) depend on program classes (with -injars), not allowed. cfr. proguard manual > introduction.